This use of AC_INCLUDES_DEFAULT looks like a typo. But it is an intentional
no-op. Weird.
2020-08-16 Bruno Haible <br...@clisp.org>
sys_ioctl: Simplify.
* m4/sys_ioctl_h.m4 (gl_SYS_IOCTL_H): Remove confusing use of
AC_INCLUDES_DEFAULT.
diff --git a/m4/sys_ioctl_h.m4 b/m4/sys_ioctl_h.m4
index 303820e..cd2735e 100644
--- a/m4/sys_ioctl_h.m4
+++ b/m4/sys_ioctl_h.m4
@@ -1,4 +1,4 @@
-# sys_ioctl_h.m4 serial 10
+# sys_ioctl_h.m4 serial 11
dnl Copyright (C) 2008-2020 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -22,7 +22,7 @@ AC_DEFUN([gl_SYS_IOCTL_H],
[dnl We cannot use AC_CHECK_DECL because it produces its own messages.
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
- [AC_INCLUDES_DEFAULT([#include <sys/ioctl.h>])],
+ [[#include <sys/ioctl.h>]],
[(void) ioctl;])],
[gl_cv_decl_ioctl_in_sys_ioctl_h=yes],
[gl_cv_decl_ioctl_in_sys_ioctl_h=no])
